The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A vehicle may include an engine speed sensor to monitor engine speed. The engine speed sensor generates an engine speed signal that indicates rotation of a crankshaft. An engine control module may determine the engine speed based on the engine speed signal.
For example, the engine speed sensor may include a Hall-effect sensor that detects passing of teeth on a gear connected to the crankshaft. The Hall-effect sensor may generate pulses that correspond to the passing of the teeth. The engine control module may determine the engine speed based on a number of pulses included in the engine speed signal during a period of time.
The teeth on the gear connected to the crankshaft may be arranged to yield a pattern of pulses when the gear is rotating. For example, a longer tooth may yield a longer pulse that indicates a position of the crankshaft. The engine control module may determine the position of the crankshaft based on the pattern of pulses detected (i.e., pattern recognition) when the gear is rotating.